This weekend I was playing Crusader Kings II, a historical strategy game covering 769 to 1453. While playing a Norse ruler, I discovered a mysterious metal box while sacking a French city. Shortly thereafter, this event happened:

The key fits the lock, and you slowly open the chest. It contains nothing but dust! As you run your hand through it, strange lights begin to manifest in the room and you close your eyes when the first ghostly apparitions appear. You hear the screams of your guards, and when you finally open your eyes again, the specters are gone… and your guards have been reduced to ash.